Liver & The Biliary System Flashcards
What are the 3 main broad functions of the liver?
- Storage - Glycogen, Vitamins, Iron, Copper
- Synthesis - Glucose, Protein, Lipids, Cholesterol, Bile
- Metabolism / Detoxification - Bilirubin, Ammonia, Drugs, Alcohol, Carbs, Lipids
What are the general symptoms of liver disease?
- Nausea
- Vomiting
- Fatigue
- Anorexia
- Abdominal Pain
What can a defect in bilirubin metabolism lead to?
Jaundice
What can a defect in Ammonia metabolism lead to?
Confusion
What can a defect in albumin synthesis lead to?
Odema / Ascites
What can a defect in synthesis of clotting factors lead to?
Bleeding / Easy Bruising
What kind of things can cause acute liver failure?
- Paracetamol overdose
- Other medications e.g. tetracycline, aspirin in children
- Acute Viral Infection e.g. EBV, CMV, Hep A/B
- Acute excessive alcohol intake
What do all chronic liver diseases end with?
Cirrhosis
How does cirrhosis arise?
- Ongoing inflammation causes fibrosis
- Associated hepatocyte necrosis
- Causes architectural changes nodules
What are the 3 main mechanisms by which alcohol can affect the liver?
- Fatty Change (weeks)- as more TAG made and deposited in the liver, initially reversible
- Alcoholic Hepatitis (years)- initially reversible
- Cirrhosis (years) - end stage, irriversible damage
How does alcoholic hepatitis present?
- Rapid onset Jaundice
- Tender Hepatomegaly (RUQ pain)
- Nausea
- Oedema
- Ascites
- Splenomegaly
What are the 2 main viruses that cause Viral Hepatitis?
Hep B - Double stranded DNA virus
Hep C - Single stranded RNA virus
What is non-alcoholic fatty liver disease (NAFLD)?
An accumulation of triglycerides and other lipids in hepatocytes
Similar pathogenesis to Alcoholic Liver Disease without the alcohol
What kind of things increase risk of non-alcoholic fatty liver disease?
- Obesity
- Diabetes
- Metabolic Syndrome (dyslipidaemia)
- Familial Hyperlipidaemia
Due to link with insulin resistance
What is Hereditary Haemochromatosis? How does it occur?
An abnormality of iron metabolism
- Increased absorption of iron from the small intestine causing excess depostion
- Autosomal recessive disorder
- Increased ferratin
How do you treat Hereditary Haemochromatosis?
Venesection treatment to remove iron load from the blood
What is Wilson’s Disease? How does it occur?
An abormality in Copper Metabolism
- Autosomal recessive disorder
- Reduced Copper secretion from the biliary system causes an accumulation in tissues
- Low Caeruloplasmin
What are some auto-immune causes of liver cirrhosis?
- Autoimmune Hepatitis
- Primary Biliary Cirrhosis
- Primary Sclerosing Colangitis
What veins form the portal vein?
What is portal hypertension?
A build up of blood in the portal venous sytem
What is the effect of a fibrotic liver on the portal venous system?
- Fibrotic liver not very expansive
- Compresses veins entering liver from portal venous system
- Increased hydrostatic pressure causes fluid to be forced out of veins → ascites
- Increased build up of pressure in splenic circulation → splenomegaly
What are the 3 most important sites of varices in portal hypertension?
- Oesophageal
- Anorectal
- Umbilical
Where are oesophageal varcies located and what can happen to them?
- Locted in the upper 2/3 of the oesophagus
- Can lead to mucosal varcies
- If rupured can cause significan haematemesis
Where are anorectal varices usually located?
Between the superior rectal and middle/ inferior rectal veins and the anus
Why are anorectal varices usually painless?
As they are above the dendate line and have visceral pain which is poorly localised
What is caput medusa?
When blood flows through the ligamentum teres (usually has no blood flow) during portal hypertension, causing superficial veins of the abdominal wall to distend
What is Hepatorenal Syndrome?
The development of Acute Kidney Injury in the presence of cirrhosis
Describe the pathophysiology of Hepatorenal syndrome
- Portal Hypertension
- Splanchnic artery vasodilation
- RAAS activated
- Renal artery vasconstriction reduces blood flow to the kidney
Label the Biliary Tree
What are gallstones formed from?
Either:
- Cholesterol
- Bile Pigments
- Or a mix of both
Which diagnostic imaging procedure would you use to identify gallstones and why?
Ulstrasound
Gallstones are radiolucent so will not show on XRay
What are some risk factors for developing gallstones?
- Diet and lifestyle rich in fat and cholesterole
- Age >40 years
- Gender: Female > Male
- Pregnancy due to stasis
- Pre-existing liver disease
What is the name given to temporary obstruction of the cystic duct that causes RUQ pain a few hours after eating a fatty meal?
Biliary Colic
Why does the pain in biliary colic arise a few hours after eating a fatty meal?
Fatty food entering the duodenum triggers the release of CCK which causes the gallbladder to move which causes the pain as contents cannot escape
How do you manage Biliary Colic?
- Analgesia
- Elective cholecystectomy
What is acute cholecystitis?
An impacted stone in the cystic duct
- initially similar presentation to biliary colic
- Inflmmatory features seen on ultrasound → thickened gallbladder
- Murphy’s Sign Positive
What is Murphy’s Sign?
- The liver, gallbladder and diaphragm are connected
- On inspiration the diaphragm flattens, lowering the liver and gallbladder
- In Murphy’s sign the Dr places their hand on the RHS of the abdomen, on inspiration it will cause pain
What is acute ascending cholangitis?
An infection of biliary tree typically due to an impacted stone in the common bile duct
Presents with Charcot’s Triad: RUQ pain, fever, jaundice
How do you manage acute ascending cholangitis?
- IV antibiotics
- Fluids
- Relieve obstruction
How can gallstones lead to acute pancreatitis?
Blockage of the pancreatic duct evokes an inflammatory response as contents cannot leave. Pancreatic enzymes start to autodigest the pancreas causing acinar cell injury and necrosis
How does acute pancreatitis present?
- Epigastric pain that radiates to the back
- Often have vomiting
- Cullen’s Sign (bruising down the tummy)
- Grey Turner’s Sign (brusing down the flanks)
